MovePrevKey method

Builder Syntax	int __fastcall MovePrevKey (bool bTree);
Delphi Syntax	Function MovePrevKey (bTree: Boolean): Integer;
Overview	Refer to Working with Key Elements.

Remarks

Updates the CurrentElement property with the key element in the DICOM Dir Data Set that immediately precedes the key element specified in the CurrentElement property. The result depends on whether the Data Set is evaluated as a tree or a list.

If the DICOM Dir Data Set is evaluated as a tree structure, this method updates the CurrentElement property with the previous key element on the same level and with the same parent as the key element specified in the CurrentElement property. Please note that the numbering of the items in this illustration is arbitrary and does not imply order.

$image\GetPvTr.gif$

If the CurrentElement property contains:	The CurrentElement property will be updated with:
Item 1	Item 2
Item 3	Item 4
Item 5	NULL
Item 6	Item 7

If the Data Set is evaluated as a list, the CurrentElement property is updated with the previous key element in the list. Please note that the numbering of the items in this illustration does indicate the order of the items when the Data Set is evaluated as a list.

$image\GetPvLst.gif$

If the CurrentElement property contains:	The CurrentElement property will be updated with:
Item 1	NULL
Item 15	Item 14
Item 5	Item 4
Item 9	Item 8
Item 22	Item 21
Item 25	Item 24

The following methods will also help you navigate the DICOM Dir Data Set as either a tree or a list:

MoveFirstKey method

MoveLastKey method

MoveNextKey method

If you evaluate the Data Set as a tree, you can also use the following methods to navigate the tree:

MoveRootKey method

MoveParentKey method

MoveChildKey method

Note:

Visual Basic users can either check the return value of the method, or capture and process errors to determine whether the MovexxxElement methods have completed successfully.